Treatment Of Hyponatremia

* Correct the serum sodium at an initial rate of 1-2 mEq/L/hr
* Replace 50% of the calculated water deficit over the first 12-24 hours
* Replace the remaining deficit over the next 24 hours
* Perform measurements of serum and urine electrolytes every 1-2 hours
* Perform serial neurologic examinations and decrease the rate of correction with improvement in symptoms
* Chronic hypernatremia with no or mild symptoms should be corrected at a rate not to exceed 0.5 mEq/L/h and/or a total of 10 mEq/d (eg, 160 mEq/L to 150 mEq/L in 24 h).
* If a volume deficit and hypernatremia are present, intravascular volume should be restored with isotonic sodium chloride prior to free-water administration.

Estimation of the replacement fluid

The TBW deficit in the hyperosmolar patient that needs to be replaced can be roughly estimated using the formula following formula:

TBW deficit = correction factor x premorbid weight x (1 - 140/Na+)
Correction factors

* Children: 0.6
* Nonelderly men: 0.6
* Nonelderly women: 0.5
* Elderly men: 0.5
* Elderly women: 0.45